DataClass

Syntax Element: type

Description

Identifies a specific type, including precision, scale, length, and nullness.

Example

database SomeDatabase
{
  types 
    int as integer,
    number ("numeric") as real,
    nstring ("nvarchar") as string;
    
  version 1.0 : initialized
  {
    design
    {
      public table T
      {
        // integer not null
        public column C1 with DataType = type(int);
        
        // integer null
        public column C2 with DataType = type(int null);
        
        // nvarchar(20) not null
        public column C3 with DataType = type(nstring(20));
        
        //nvarchar(100) null
        public column C4 with DataType = type(nstring(100) null);
        
        // numeric(10, 3) not null
        public column C5 with DataType = type(number(10, 3));
        
        // numeric(12, 4)
        public column C6 with DataType = type(number(12, 4) null);
      }
    }
  }
}

Notes

• Rarely do you want to map something like a T-SQL INT to anything other than an integer type in your client. To avoid re-specifying such mappings, every type is derived from a base type defined using the types keyword.

Related Use Cases

• Specifying design separately from construction
• Getting compiler feedback on your database design
• Eliminating duplication between client and database code
• Deriving creation scripts from design
• Keeping clients coupled to the current version
• Leveraging a version's proxy in a client
• Transition testing

Other Actions

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